Binding/grinding from back end.

[quikveedb2]

I've got a noise, a kind of binding/grinding, most noticeable at low speed, and turning, coming from the back end of the car. It started as something I only noticed after an hour or more on the road, and has progressed to a daily occurrence, regardless of distance. Thoughts, and places to start looking would be much appreciated! Tia.

[phenobarb1]

Bad wheel bearing?
Stuck brake caliper?
Differential that is about to explode?

Those would be my guesses in order of likelihood.

[jlevie]

When the noise is present, does it change if you very lightly apply the brakes? If so you may have a siticking caliper. Another check would be to lightly apply the parking brake and see if the noise changes. If neither of those checks has any affect I'd suspect wheel bearings and/or half shafts.

[quikveedb2]

Application of the brakes does not seem to make a difference, I think a stuck caliper might be out as far as suspects goes. It happens regardless of forward or backwards motion, if that makes any kind of difference. Is there a way to check wheel bearings and half shafts, i.e. lateral play or noise when rotated off the ground? I hope it's not the diff, that would suck. Thanks for the replies, guys.

[nolo200]

If it happens mostly on acceleration I'd say halfshaft. I just had the same problem and couldn't track it down until the cv joint exploded driving down the interstate.

[quikveedb2]

Not really noticeable under acceleration, very much more so at parking lot speeds, and coasting as low speed. It is getting progressively worse, so I'm sure to find out sooner or later. I feel/hear nothing at speeds over 10mph-ish currently. I'd rather nip it in the bud than have to deal with an exploded anything, as it is my daily. Hopefully I can get it off the ground soon for some investigation, but work/gf/family/moving/life keeps getting in my way.

[jlevie]

Get the rear of the car in the air and spin each wheel. A bad bearing will make noise and feel rough. You may have to remove the brake pads as they may drag slightly and mask the bearing sounds.

[quikveedb2]

That makes sense, I'll give it a shot. Thanks for the help.

[101]

quikveedb2:

Did you get a chance to do any more checking on this? I'm having a similar issue on a 87 eta (2.93 LSD rear axle)

I checked for binding e-brake cables and calipers and those seem to check out OK.

We experimented further in a parking lot. My buddy drove around and I stood outside. The car is fine when going in a straight line, but while turning the back wheels seem to bind and the tires chirp. Once the car is going straight again, all is well.

I recently replaced the fluid with the Valvoline Durablend 80W 90 Synthetic blend gear oil. That was about 500 miles ago. The old fluid did not look bad at all, and no metal.

Question:

Anyone have bad experience using this Valvoline fluid? Should I put any additives in it?

Or is my differential ready to take a dump?



TIA,

Keith

[quikveedb2]

At this point I suspect wheel bearings, I lowered the car last summer and I've put significant miles on it since then. It seems likely that with the added camber they'd go south, since they're almost 25 years old. I'll keep you posted.

[quikveedb2]

Got he car off the ground today, a blown out outboard CV boot on the right side of the car is my main suspect. The drive shaft also has significant play, but I'm gonna start with the half shaft, based on the fact that the noise was most noticeable after extended driving (no grease in CV = heat), and while turning right.

[Ceeker]

also, check your rear backing plate -parking brake shoes; typically they rot out and the hold done pin comes through breaking the shoes free. Sometimes this creates a binding, grinding noise. you might have two problems at the same time one over shadowing the other.

[quikveedb2]

Thanks for the tip!

[quikveedb2]

Sadly I'm still fighting this problem, I've eliminated the binding/stuck brake caliper since I replaced the pads, rotors, & wear sensors in the fall & everything was working fine. I've also serviced the diff & installed some fresh Lucas GL-5. I really don;t drive long distances all that often, so it's rarely even noticeable, but since I've been commuting to & from Denver a lot lately it's back on my fix-it list. I guess I'll be buying/rebuilding some half shafts some time this summer. The rear sub-frame needs new bushings, so it'll probably get rolled into that project...

[Nowayman]

I don't know if this helps, but I just had the same thing going on. When I'd back out of a spot and turn I'd hear popping and grinding from the right rear. It ended up being my e brake shoes. A spring broke and they were hanging up. I installed new rotors about a month ago and they looked fine. I changed the shoes and everything is fine now. I'd recommend taking a closer look at those.